Re: [EXT] Re: [PATCH 2/2] arm64: dts: imx93: add DDR controller node

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 15/09/2023 04:39, Xu Yang wrote:
> Hi Krzysztof,
> 
>> On 14/09/2023 12:20, Xu Yang wrote:
>>> Add DDR controller node which will be used by EDAC driver later, also
>>> move the DDR PMU node as the subnode of the DDR controller.
>>>
>>> Signed-off-by: Ye Li <ye.li@nxp.com>
>>> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
>>> ---
>>>  arch/arm64/boot/dts/freescale/imx93.dtsi | 18 ++++++++++++++----
>>>  1 file changed, 14 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/arch/arm64/boot/dts/freescale/imx93.dtsi b/arch/arm64/boot/dts/freescale/imx93.dtsi
>>> index 6f85a05ee7e1..992bdeef70cd 100644
>>> --- a/arch/arm64/boot/dts/freescale/imx93.dtsi
>>> +++ b/arch/arm64/boot/dts/freescale/imx93.dtsi
>>> @@ -917,10 +917,20 @@ media_blk_ctrl: system-controller@4ac10000 {
>>>                       status = "disabled";
>>>               };
>>>
>>> -             ddr-pmu@4e300dc0 {
>>> -                     compatible = "fsl,imx93-ddr-pmu";
>>> -                     reg = <0x4e300dc0 0x200>;
>>> -                     interrupts = <GIC_SPI 90 IRQ_TYPE_LEVEL_HIGH>;
>>> +             ddr: memory-controller@4e300000 {
>>> +                     compatible = "simple-mfd";
>>
>> No, that's not allowed alone.
> 
> Well, then how should I modify this compatible?

You need specific compatible, just like everywhere else. You can use
"git grep simple-mfd" or "git grep simple-mfd -- arch/arm*" or on
bindings to figure this out.

Just remember that simple-mfd means children do not depend on anything
provided by the parent. You cannot later remove it "just because" or
"oh, now I want driver". That would affect users of DTS.

> 
>>
>> It does not look like you tested the DTS against bindings. Please run
>> `make dtbs_check W=1` 
>>
> 
> I just run the check script, it seems no warnings for this node.

Right, I always forget we did not convert simple-mfd to DT schema, so
the warnings are only for syscon.

Best regards,
Krzysztof